+2: Put a +1/+1 counter on all artifact creatures you control. Put a charge counter on all non-creature artifacts you control.-3: Remove all counters from all other permanents. For each counter removed this way, put a loyalty counter on Urza Planeswalker.-15: Exile all other permanents. For each black permanent exiled this way, its controller loses 3 life.

Now, why don't we create a card for the other planeswalkers that appear in the storyline? Like this un-innovative design:

Jaya Ballard, Master of Fire

Planeswalker - Jaya (Loyalty:2)

+2: Destroy target blue permanent.+1: Jaya Ballard, Master of Fire deals 3 damage to target creature or player. A creature dealt damage this way can't be regenerated this turn.-7: Jaya Ballard deals 6 damage to each creature and each player.

Or this:

Freyalise in Skyshroud

Planeswalker - Freyalise (Loyalty:4)

+1: Search your library for a basic land card, put it onto the battlefield, then shuffle your library.-1: Target creature gets +3/+3 and gains trample until end of turn.-8: You get an emblem with "Permanents you don't control don't untap during their controllers' untap steps.

Jaya's +2 is a little swingy. It's either Vindicate for everything but lands, Eldrazi, and most artifacts, or it's worthless.

Urza's -15 is...do color hosers regularly show up on planeswalkers? Also, it's kind of a bad one. (And why is blue hosing black?) Finally, I expect more Phyrexian-like mechanics for Urza. He admitted to his admiration for Yawgmoth, after all. And the Extruder flavor text.

Freyalise's +2 is...I'm not sure "fetch a basic land" is a + ability. And her -8 is the spell she ended.

Jaya's +2 is a little swingy. It's either Vindicate for everything but lands, Eldrazi, and most artifacts, or it's worthless.

Urza's -15 is...do color hosers regularly show up on planeswalkers? Also, it's kind of a bad one. (And why is blue hosing black?) Finally, I expect more Phyrexian-like mechanics for Urza. He admitted to his admiration for Yawgmoth, after all. And the Extruder flavor text.

Freyalise's +2 is...I'm not sure "fetch a basic land" is a + ability. And her -8 is the spell she ended.

I designed Jaya to be the exact counterpart to her spellshaper version, and I know the +2 is kind of narrow. That's why I designed the +1 ability to be overly powerful... I made a a mistake in my original post, the 2nd ability should be +1 instead of -1. +1 and deal 3 damage surely is overpowered, but as a whole Jaya would seldom survive the 2nd turn after she ETB so that would just be a 3 mana Incinerate.

Urza's ultimate reflects his hatred to Pherexia but at the same time I understand it's not possible to put a narrow color hoser as an ultimate. That's why I designed his ultimate to be useful in general but particularly deadly for black.

Freyalise costs 5 mana to cast, so she should be kick-ass even on the first turn she ETB, or she is completely useless (who would fetch a basic land for 5 mana AND -1 loyalty?). That said, I realize +2 is probably too much, so I reduce it to +1. Regarding her ultimate, I draw the idea from Freyalise's Winds, not as a reference to the World Spell (afterall, the World Spell should not be one-sided...)

+2: Other players can't cast spells this turn.0: Exile target creature you control, then return it to the battlefield under its owner's control.-2: Until your next turn, creatures without flying can't attack you or a planeswalker you control.-10: Exile all other permanents. You may put a creature card from your hand onto the battlefield without paying its mana cost. It has haste.